Non-uniform sampling strategies for continuous correction based trajectory estimation

Sliding window estimation is widely used for online simultaneous localization and mapping. While increasing the sliding window size generally yields improved accuracy, it also comes at an increase in computational cost. In order to reduce this cost, we propose smarter non-uniform sampling of the trajectory representation over the sliding window. This non-uniform temporal resolution is possible with continuous-time representations that allow freely adjustable knots location. Four strategies for selecting the knots location are presented and evaluated based on a real data laser-odometry SLAM problem. The results clearly show that non-uniform distributions of knots can be superior to uniform distribution in terms of accuracy per computation time.